Globe warming and energy shortage are the two environment problems we are facing today. For lightening these problems, in respect of electric power usage, what is wished is to save electric energy and further reduce heat discharge due to electric power consumption as far as possible.
However, in a modern enterprise environment, more and more IT devices come into use, and most of them are powered on all the time. Thus, just these IT devices will consume large amounts of electric energy.
Especially in the recent years, data center/application system (distributed computing environment) power usage is the first infrastructure issue the IT environment of an enterprise faces. Five years ago, the average power consumption per rack was 1 kW to 3 kW. With requirements for processor cycles, memory, and storage continuing to increase, the density of the devices packed into each rack increases accordingly. It is now common for a typical rack to consume 5 kW to 7 kW of electric power, with each rack of high-density blade servers consuming 24˜30 kW of electric power. Due to the dramatic increase in power consumption, the cost on electric power consumption of data center/application system increases, which places a large burden on the data center/application system for delivering this much electric power and cooling IT devices by using electric power additionally. It is easy to see why power management for data center/application system is so important.
Some of these IT devices do have power management capabilities, such as the ACPI (Advanced Configuration and Power Interface) in most PCs.
In the ACPI standard, some kinds of power management status are defined for certain kinds of IT components or devices, such as CPU, disk, CD-ROM, etc. By using ACPI, the devices complying with the ACPI standard may support to switch among these power management statuses at the hardware or software level.
However, for a data center/application system, although some of IT devices therein have ACPI and the IT devices may be network connected, they have to be configured and managed separately in order to bring ACPI into play.
One issue is that ACPI standard mainly focuses on defining a complicated power management interface for low level devices or components. For a data center/application system, thousands of devices therein may belong to hundreds of different device types. For resources and components contained in different types of devices being not completely identical generally, the specific ACPI settings related to resources and components of the different types of devices are also different generally. Therefore, configurations and managements need to be performed separately for these different types of IT devices.
At present, there is no central and automatic power management mechanism to monitor and manage the power consuming in a data center/application system (distributed computing environment).
In theory, it is wished that, with the help of ACPI like interface, the application developers can develop applications which can intelligently manage the power consumption of data center/application system to achieve the target of saving energy while implementing their own specific functions during execution. However, in practice, this is impractical for a large data center/application system. For example, it is almost impossible for the application developer to fully understand the power management details of thousands of different types of devices in the data center/application system and set for the devices at the application development stage, suitable power management oriented actions that should be taken during application running.
Therefore, there is a need for such a power management approach which can centrally manage the power consumption of data center/application system and can provide a power management interface for application development so that the central power management design during application running can be put forward to the application development stage.